Monitoring device based on optical fiber sensor cable joint

Abstract

According to the monitoring device based on the optical fiber sensor cable joint, the temperature detection unit adopts an optical fiber temperature sensor to measure a cable joint temperature signal and an environment temperature signal, the measured cable joint temperature signal is corrected according to the influence of the environment temperature signal on the measured cable joint temperature signal, and the corrected signal enters the fault fitting unit; the current detection unit adopts an optical fiber current sensor to measure current during cable operation, power consumption is calculated according to a current signal, the power consumption enters the fault fitting unit after being filtered, the partial discharge detection unit adopts an optical fiber sonic sensor to detect a partial discharge signal, and the partial discharge signal enters the fault fitting unit after being converted by a transformer and a differentiator; the fault fitting unit is used for avoiding instantaneous false triggering through bidirectional triggering alarm when the measured cable joint temperature signal is abnormal or the partial discharge is abnormal after the power consumption superposition correction, and is used for rapidly triggering and timely alarming when the partial discharge signal is abnormal, and the action is reliable.

Description

Technical Field

[0001] The present invention belongs to the technical fields of optical fiber sensing and power equipment monitoring, and particularly relates to a monitoring device based on an optical fiber sensor for a cable joint. Background Art

[0002] Since the cable operates under live conditions for a long time, the probability of faults such as flammability and aging is relatively high. Especially for the joints between cables, faults are likely to occur due to an increase in contact resistance, the influence of the external environment, local discharges caused by the operation of large currents in the cables, and defects in the cable insulation materials, posing potential safety hazards to production operations. Therefore, its monitoring and maintenance are particularly important.

[0003] Since various faults occurring at the cable joint are not a sudden process but a gradual one, and generally are accompanied by an increase in the temperature of the joint. Existing technologies usually set up temperature-sensing elements at the cable joint to detect the temperature. When the temperature at the cable joint exceeds the permitted temperature, the alarm goes off. In the prior art, a cable joint fault monitoring system and monitoring method with the application number 202010602234.9 detects the temperature of the cable joint and the ambient temperature, takes the difference between the two as the temperature of the cable joint body, calculates the normal temperature of the cable joint based on the operating current value, and calculates the difference between the normal temperature of the cable joint and the current temperature of the cable joint body at this time, and issues an abnormal alarm based on the difference.

[0004] On the one hand, due to the influence of the ambient temperature on the temperature of the cable joint, which is directly related to the thermal conductivity coefficient corresponding to the size and material of the cable joint housing, there is a deviation in taking the difference between the two as the temperature of the cable joint body. On the other hand, the current value is not constant, there is an overcurrent phenomenon, and local discharges will also cause the temperature to rise. Therefore, calculating the normal temperature of the cable joint based on the operating current value and using the difference calculated from the current temperature of the cable joint body at this time as the basis for abnormal alarm is not reliable enough. Summary of the Invention

[0005] In view of the above situation, to overcome the defects of the prior art, the present invention provides a monitoring device based on an optical fiber sensor for a cable joint, effectively solving the problems of temperature calculation deviation in the prior art and the lack of reliability in using the difference between the calculated temperature value and the normal temperature of the cable joint calculated from the operating current value as the basis for abnormal alarm.

[0006] Its technical solution includes a temperature detection unit, a current detection unit, a partial discharge detection unit, and a fault fitting unit. The temperature detection unit uses an optical fiber temperature sensor to measure the temperature signal and ambient temperature signal of the cable joint, and gives a corrected measured cable joint temperature signal based on the influence of the ambient temperature signal on the measured cable joint temperature signal, and enters the fault fitting unit. The current detection unit uses an optical fiber current sensor to measure the current during the operation of the cable, calculates the power consumption based on the current signal, and the power consumption enters the fault fitting unit after filtering; The partial discharge detection unit uses an optical fiber acoustic wave sensor to detect the partial discharge signal, which enters the fault fitting unit after being transformed by a transformer and converted by a differentiator; When the fault fitting unit measures that the temperature signal of the cable joint is abnormal or the partial discharge is abnormal after the power consumption superposition correction, the triode Q1 connects +24V to one end of the coil LA, the temperature signal of the cable joint measured after the power consumption superposition correction is added to the base of the triode Q3, the triode Q3 connects to one end of the coil LA, the coil LA is powered on, and the cable joint fault is fitted.

[0007] Preferably, the temperature detection unit includes an optical fiber temperature sensor, which respectively measures the temperature signal of the cable joint and the ambient temperature signal. The temperature signal of the cable joint is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to one end of the grounding capacitor C1, one end of the resistor R3, the negative electrode of the diode D1, the positive electrode of the diode D2, and the positive electrode of the diode D3. The negative electrode of the diode D3 is connected to the negative electrode of the voltage regulator Z1. The ambient temperature signal is connected to the X pin of the multiplier ID1. The Y pin of the multiplier ID1 is connected to the thermal conductivity corresponding to the size * material of the cable joint housing. The U0 pin of the multiplier ID1 is respectively connected to one end of the resistor R1 and one end of the resistor R2. The other end of the resistor R1 is connected to the non-inverting input terminal of the operational amplifier AR1. The inverting input terminal of the operational amplifier AR1 is connected to the other end of the inductor L1 through the resistor R3. The output terminal of the operational amplifier AR1 is respectively connected to the upper end of the bidirectional voltage regulator SZ1 and the common terminal of the switch K1. The lower end of the bidirectional voltage regulator SZ1 is connected to the ground. The normally open contact of the switch K1 is connected to the positive electrode of the diode D1. The normally closed contact of the switch K1 is connected to the inverting input terminal of the operational amplifier AR2. The non-inverting input terminal and the output terminal of the operational amplifier AR2 are connected to the negative electrode of the diode D2.

[0008] Preferably, the fault fitting unit includes a triode Q2 and a triode Q3. The base of the triode Q2 is respectively connected to the other end of a resistor R16 and the negative electrode of a diode D5. The positive electrode of the diode D5 is respectively connected to the positive electrode of a grounded electrolytic capacitor E3 and one end of a resistor R21. The other end of the resistor R21 is respectively connected to one end of a resistor R20, the positive electrode of a voltage stabilizing diode Z1, and one end of a resistor R7. The other end of the resistor R7 is connected to the negative electrode of the voltage stabilizing diode Z1. The emitter of the triode Q2 is connected to the drain of a field effect transistor T1. The source of the field effect transistor T1 is connected to the power supply +3.8V0. The gate of the field effect transistor T1 is respectively connected to one end of a grounded resistor R19, the positive electrode of a grounded electrolytic capacitor E2, one end of a resistor R18, and the positive electrode of an electrolytic capacitor E1. The other end of the resistor R18 is respectively connected to the negative electrode of the electrolytic capacitor E1 and the positive electrode of a voltage stabilizing diode Z2. The collector of the triode Q2 is connected to one end of a resistor R17. The other end of the resistor R17 is connected to the base of a triode Q1. The emitter of the triode Q1 is connected to the power supply +24V0. The collector of the triode Q1 is respectively connected to one end of a coil LA and the negative electrode of a diode D4. The other end of the resistor R20 is connected to the base of the triode Q3. The collector of the triode Q3 is respectively connected to the other end of the coil LA and the negative electrode of the diode D4. The emitter of the triode Q3 is connected to the ground through a resistor R22.

[0009] The beneficial effects of the present invention are as follows: Measuring the temperature of the cable joint after correction and power consumption superposition can better reflect the real temperature. Secondly, the abnormal comparison and judgment adopt the cable overheating temperature and partial discharge detection standards, and trigger alarms bidirectionally to avoid instantaneous false triggering. When the partial discharge signal is abnormal, it triggers rapid conduction and alarms in a timely manner, with reliable actions. Each unit can be configured with a microprocessing unit, and the microprocessing unit communicates with the remote end through a communication module to remotely monitor the operating status of the cable joint and analyze faults. Brief Description of the Drawings

[0010] Figure 1 is the circuit schematic diagram of the present invention. Detailed Embodiments

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0012] The following will be further described in detail with reference to the attached Figure 1 description of the present invention for the specific implementation manners.

[0013] Monitoring device based on an optical fiber sensor cable joint, comprising a temperature detection unit, a current detection unit, a partial discharge detection unit, and a fault fitting unit. The temperature detection unit uses an optical fiber temperature sensor installed at the cable joint to measure the temperature signal of the cable joint, which is output after being filtered by an inductor and a capacitor LC filter. An optical fiber temperature sensor installed outside the cable joint housing is used to measure the ambient temperature signal, and the product of the size of the cable joint housing and the thermal conductivity corresponding to the housing material is calculated to obtain the influence coefficient h. The ambient temperature signal and the influence coefficient h enter the multiplier D1 to obtain the influence temperature signal. The operational amplifier AR1 compares the ambient temperature signal and the measured cable joint temperature signal. The operational amplifier AR1 outputs a positive difference, which, after being regulated by the bidirectional voltage regulator SZ1, causes the switch K1 to act. The influence temperature signal passes through the normally open contact and the operational amplifier AR2, which is also an inverter, and outputs a negative influence temperature signal to negatively correct the measured cable joint temperature signal. Conversely, when the ambient temperature signal is lower than the measured cable joint temperature signal, the internal temperature of the housing dissipates heat outward, and the measured value is relatively lower than the true value. The operational amplifier AR1 outputs a negative difference, and the switch K1 does not act. The influence temperature signal passes through the normally closed contact and the diode D1, and outputs a positive influence temperature signal to positively correct the measured cable joint temperature signal, and the corrected measured cable joint temperature signal is given and enters the fault fitting unit; The current detection unit uses an optical fiber current sensor to measure the current during cable operation. The square of the current signal (which can be calculated by the product of an analog multiplier) enters the multiplier ID2. The multiplier ID2 also receives the product of the cable internal resistance R and the time signal t. The multiplier ID2 performs a product operation to calculate the power consumption, which is the heat generated by the resistance when current passes through, and this part of the heat is the power loss. The power consumption signal enters the fault fitting unit after being filtered by an average filter; The partial discharge detection unit uses an optical fiber acoustic wave sensor to detect the partial discharge signal. Partial discharge PD is a common insulation defect phenomenon. After detection, the signal is transformed by a transformer. The high-frequency partial discharge signal is coupled to the primary coil of the transformer T1 through the capacitor C2, and the low-frequency partial discharge signal is coupled to the primary coil of the transformer T1 through the inductor LA to reduce the mutual influence between high and low frequencies. Then, the voltage and frequency of the transformer T1 are transformed, and the output is from the secondary coil. Finally, it enters the differential amplitude conversion to suppress the common-mode noise and enhance the differential signal and enters the fault fitting unit; The fault fitting unit receives the corrected measured temperature signal of the cable joint through diode D3. After superimposing with the power consumption signal, the total temperature signal of the cable joint is obtained. By effectively indirectly measuring the heating and superimposing the measured temperature signal of the cable joint through the power consumption signal, the total temperature signal of the cable joint can be reflected more accurately and in advance. When the total temperature signal is abnormal, that is, when it exceeds the overheating temperature of the cable, after the inverse time limit and then through delayed charging, it is applied to the base of triode Q1. Or when the partial discharge is abnormal, the starting voltage of the partial discharge should not exceed 1.25 times the rated voltage. When it exceeds, it is abnormal. The divider composed of operational amplifier AR5 and multiplier ID3 performs ratio quantization. The quantization value becomes a weak electrical signal on the one hand, and on the other hand, due to the effect of delay, it is applied to the base of triode Q1, triggering triode Q2 to conduct, and then triggering triode Q1 to conduct. Triode Q1 connects +24V to one end of coil LA. The power consumption superimposed with the corrected measured temperature signal of the cable joint is applied to the base of triode Q3. Triode Q3 connects to one end of coil LA. Coil LA is energized to fit the cable joint fault. The normally open contact of coil LA connects the indicator light, buzzer, etc. to give a fault alarm. When triode Q3 conducts and triggers triode Q1 to conduct after a delay, an alarm is given to avoid instantaneous false triggering. At the same time, partial discharge will also cause temperature rise. When the partial discharge signal is abnormal, it is fed back to the base of the field effect transistor, changing the emitter resistance of triode Q2 to make triode Q2 conduct quickly and trigger the alarm in time. Compared with the prior art, measuring the temperature of the cable joint after correction and power consumption superposition can better reflect the real temperature. Secondly, the abnormal comparison and judgment adopt the overheating temperature of the cable and the partial discharge detection standard, and give a two-way trigger alarm to avoid instantaneous false triggering. When the partial discharge signal is abnormal, triode Q2 is made to conduct quickly to give an alarm in time, and the action is reliable. Each unit can be configured with a microprocessing unit. The microprocessing unit communicates with the remote end through a communication module to remotely monitor the operating state of the cable joint and analyze faults.

[0014] On the basis of the above solution, the temperature detection unit uses an optical fiber temperature sensor installed at the cable joint to measure the temperature signal of the cable joint. After filtering through an inductor and a capacitor LC, it is output. An optical fiber temperature sensor installed outside the cable joint housing measures the ambient temperature signal. The optical fiber temperature sensor can adopt the YF-200 point-type optical fiber temperature sensor, which has a wide temperature measurement range, up to -40°C to 200°C, and is a non-contact measurement, which can avoid problems such as heat transfer error and thermal inertia in traditional contact temperature measurement, and has strong anti-interference ability, which can reduce the influence of strong electromagnetic interference in the external environment on temperature measurement. Since when the ambient temperature rises, the heat is conducted through the housing material, causing the temperature inside the housing to rise accordingly. Conversely, when the ambient temperature drops, the temperature inside the housing will also decrease accordingly. Therefore, the product of the size of the cable joint housing and the thermal conductivity corresponding to the housing material is calculated to obtain the influence coefficient h. When the size and housing material are fixed, the influence coefficient h is a constant. The ambient temperature signal and the influence coefficient h enter the multiplier D1 to obtain the influence temperature signal. The influence temperature signal is corrected positively through the normally closed contact of the switch K1 or negatively through the moving contact to measure the temperature signal of the cable joint. Specifically, the operational amplifier AR1 is used to compare the ambient temperature signal and the measured cable joint temperature signal. When the ambient temperature signal is higher than the measured cable joint temperature signal, the temperature inside the housing also rises accordingly, and the measured value is relatively higher than the true value. The operational amplifier AR1 outputs a positive difference. After being stabilized by the bidirectional voltage regulator tube SZ1, the switch K1 is actuated. The influence temperature signal passes through the moving contact and the operational amplifier AR2, that is, the inverter, and outputs a negative influence temperature signal to correct the measured cable joint temperature signal negatively. Conversely, when the ambient temperature signal is lower than the measured cable joint temperature signal, the temperature inside the housing dissipates heat outward, and the measured value is relatively lower than the true value. The operational amplifier AR1 outputs a negative difference, and the switch K1 does not actuate. The influence temperature signal passes through the normally closed contact and the diode D1, and outputs a positive influence temperature signal to correct the measured cable joint temperature signal positively, reducing the influence of the ambient temperature on the measured cable joint temperature inside the housing. It includes an optical fiber temperature sensor. The optical fiber temperature sensor respectively measures the cable joint temperature signal and the ambient temperature signal. One end of the cable joint temperature signal is connected to one end of the inductor L1. The other end of the inductor L1 is respectively connected to one end of the grounded capacitor C1, one end of the resistor R3, the negative electrode of the diode D1, the positive electrode of the diode D2, and the positive electrode of the diode D3. The negative electrode of the diode D3 is connected to the negative electrode of the voltage regulator tube Z1. The ambient temperature signal is connected to the X pin of the multiplier ID1. The Y pin of the multiplier ID1 is connected to the thermal conductivity corresponding to the size * material of the cable joint housing. The U0 pin of the multiplier ID1 is respectively connected to one end of the resistor R1 and one end of the resistor R2. The other end of the resistor R1 is connected to the non-inverting input terminal of the operational amplifier AR1. The inverting input terminal of the operational amplifier AR1 is connected to the other end of the inductor L1 through the resistor R3,The output terminal of the operational amplifier AR1 is respectively connected to the upper end of the bidirectional voltage regulator tube SZ1 and the common terminal of the switch K1. The lower end of the bidirectional voltage regulator tube SZ1 is connected to the ground. The normally open contact of the switch K1 is connected to the positive electrode of the diode D1. The normally closed contact of the switch K1 is connected to the inverting input terminal of the operational amplifier AR2. The non-inverting input terminal and the output terminal of the operational amplifier AR2 are connected to the negative electrode of the diode D2.

[0015] On the basis of the above solution, the current detection unit uses a BMS series fiber optic current sensor to measure the current during cable operation. It can use the optical principle to measure the current signal, has high precision, high sensitivity, strong anti-electromagnetic interference ability, and has a digital interface and remote communication function, and can realize remote measurement and monitoring. The square of the current signal enters the multiplier ID2. The multiplier ID2 also accesses the product of the cable internal resistance R (the calculation formula for the cable internal resistance is R = ρl / S, where R is the internal resistance of the cable, ρ is the resistivity of the wire material, l is the length of the cable, and S is the cross-sectional area of the cable) and the time signal t (sampling time). The multiplier ID2 calculates the power consumption through product operation. The power consumption is the heat generated when the current passes through the resistor, and this part of the heat is the power loss of the electric energy. The power consumption is filtered by the average filter composed of the operational amplifier AR3, resistors R4 - R6, and electrolytic capacitor E3 and enters the fault fitting unit. It includes a fiber optic current sensor that measures the current during cable operation. The squared current signal is added to the X pin of the multiplier ID2. The Y pin of the multiplier ID2 is connected to the cable resistance value R * time t. The U0 pin of the multiplier ID2 is connected to one end of the resistor R4. The other end of the resistor R4 is respectively connected to the inverting input terminal of the operational amplifier AR3, one end of the resistor R5, and the positive electrode of the electrolytic capacitor E3. The non-inverting input terminal of the operational amplifier AR3 is connected to the ground through the resistor R6. The output terminal of the operational amplifier AR3 is respectively connected to the other end of the resistor R5, the negative electrode of the electrolytic capacitor E3, and the negative electrode of the voltage regulator tube Z1.

[0016] Based on the above solution, the partial discharge detection unit uses a fiber optic acoustic wave sensor to detect partial discharge signals. Partial discharge (PD) is a common insulation defect phenomenon. Usually, a fiber optic acoustic wave sensor, also known as an EFPI sensor, is used for partial discharge detection. After detection, the signal is transformed by a transformer. The high-frequency partial discharge signal is coupled to the primary coil of transformer T1 through capacitor C2, and the low-frequency partial discharge signal is coupled to the primary coil of transformer T1 through inductor LA, which is used to reduce the mutual influence between high and low frequencies. Then, the voltage and frequency of transformer T1 are transformed and output from the secondary coil. Finally, it enters the differential amplitude conversion composed of operational amplifier AR4 and resistors R9 - R12 to suppress common-mode noise and enhance the differential signal, that is, the difference part between the two signals, and then enters the fault fitting unit. In this way, the accuracy and reliability of partial discharge detection are jointly improved. It includes a fiber optic acoustic wave sensor. One end of the partial discharge signal detected by the fiber optic acoustic wave sensor is connected to one end of inductor LA, one end of resistor R8, and one end of capacitor C2. The other end of capacitor C2 is connected to one end of the primary coil of transformer T1. The other end of the partial discharge signal detected by the fiber optic acoustic wave sensor is connected to the other end of inductor LA, the other end of resistor R8, and the other end of the primary coil of transformer T1. One end of the secondary coil of transformer T1 is connected to one end of inductor LB. The other end of inductor LB is connected to one end of capacitor C3. The other end of capacitor C3 is respectively connected to one end of resistor R9 and one end of resistor R10. One end of the secondary coil of transformer T1 is respectively connected to the other end of resistor R9 and one end of resistor R12. The other end of resistor R10 is respectively connected to the inverting input terminal of operational amplifier AR4 and one end of resistor R11. The other end of resistor R12 is respectively connected to the non-inverting input terminal of operational amplifier AR4. The output terminal of operational amplifier AR4 is respectively connected to the negative electrode of voltage regulator Z2 and one end of resistor R13. The other end of resistor R13 is respectively connected to one end of resistor R14 and the inverting input terminal of operational amplifier AR5. The non-inverting input terminal of operational amplifier AR5 is connected to ground through resistor R15. The output terminal of operational amplifier AR5 is respectively connected to pin Y of multiplier ID3 and one end of resistor R16. Pin Y of multiplier ID3 is connected to the reference partial discharge signal. Pin U0 of multiplier ID3 is connected to the other end of resistor R14.

[0017] On the basis of the above solution, the fault fitting unit receives the corrected measured cable joint temperature signal through diode D3. After being superimposed with the power consumption signal, the total cable joint temperature signal is obtained. By effectively indirectly measuring the heat generation through the power consumption signal and superimposing the measured cable joint temperature signal, it can more accurately and predictably reflect the total cable joint temperature signal. When the total temperature signal is abnormal, that is, when it exceeds the cable overheat temperature, it goes through the inverse time limit of the parallel-connected voltage regulator Z1 and resistor R7, and then through resistor R21 and electrolytic capacitor E1 for delayed charging, and is applied to the base of triode Q1. Or when the partial discharge is abnormal, for different types of cables, there are usually corresponding partial discharge detection standards and specifications. For example, for cables with a rated voltage of 6 / 10 kV and below, the partial discharge starting voltage should not exceed 1.25 times the rated voltage. When it exceeds, it is abnormal. In order to facilitate signal processing in this application, the partial discharge signal and 1.25 times the rated voltage are ratio-quantified by a divider composed of operational amplifier AR5 and multiplier ID3. The quantization value becomes a weak electrical signal on the one hand, and on the other hand, due to the effect of delay, it is applied to the base of triode Q1, triggering triode Q2 to conduct, and then triggering triode Q1 to conduct. Triode Q1 connects +24V to one end of coil LA. The power consumption superimposed with the corrected measured cable joint temperature signal is applied to the base of triode Q3. Triode Q3 connects to one end of coil LA. Coil LA is energized to fit the cable joint. The normally open contact of coil LA turns on the indicator light, buzzer, etc. for fault alarm. When triode Q3 conducts and delays to trigger triode Q1 to conduct, an alarm is given to avoid instantaneous false triggering. At the same time, partial discharge will also cause temperature rise. When the partial discharge signal is abnormal, it is fed back to the base of the field effect transistor, changing the emitter resistance of triode Q2 to make triode Q2 conduct quickly and trigger the alarm in time. Compared with the prior art, measuring the cable joint temperature after correction and power consumption superposition can more accurately reflect the real temperature. Secondly, the abnormal comparison and judgment adopt the cable overheat temperature and partial discharge detection standards, and trigger the alarm bidirectionally to avoid instantaneous false triggering. When the partial discharge signal is abnormal, triode Q2 is made to conduct quickly to give an alarm in time, and the action is reliable. It includes triode Q2 and triode Q3. The base of triode Q2 is respectively connected to the other end of resistor R16 and the negative electrode of diode D5. The positive electrode of diode D5 is respectively connected to the positive electrode of the grounded electrolytic capacitor E3 and one end of resistor R21. The other end of resistor R21 is respectively connected to one end of resistor R20 and the positive electrode of voltage regulator Z1, and one end of resistor R7. The other end of resistor R7 is connected to the negative electrode of voltage regulator Z1. The emitter of triode Q2 is connected to the drain of field effect transistor T1. The source of field effect transistor T1 is connected to power supply +3.8V0, the gate of field effect transistor T1 is respectively connected to one end of grounding resistor R19, the positive electrode of grounding electrolytic capacitor E2, one end of resistor R18, and the positive electrode of electrolytic capacitor E1. The other end of resistor R18 is respectively connected to the negative electrode of electrolytic capacitor E1 and the positive electrode of voltage stabilizing diode Z2. The collector of triode Q2 is connected to one end of resistor R17, the other end of resistor R17 is connected to the base of triode Q1, the emitter of triode Q1 is connected to power supply +24V0, the collector of triode Q1 is respectively connected to one end of coil LA and the negative electrode of diode D4. The other end of resistor R20 is connected to the base of triode Q3, the collector of triode Q3 is respectively connected to the other end of coil LA and the negative electrode of diode D4, and the emitter of triode Q3 is connected to ground through resistor R22.

Claims

1. A monitoring device based on a fiber optic sensor cable joint, comprising a temperature detection unit, a current detection unit, a partial discharge detection unit, and a fault fitting unit, characterized in that: The temperature detection unit uses an optical fiber temperature sensor to measure the cable joint temperature signal and the ambient temperature signal, and according to the influence of the ambient temperature signal on the measured cable joint temperature signal, a corrected measured cable joint temperature signal is given and enters the fault fitting unit; The current detection unit uses an optical fiber current sensor to measure the current of the cable when it is running, and the power consumption is calculated according to the current signal, and the power consumption is filtered and enters the fault fitting unit; The partial discharge detection unit uses an optical fiber acoustic wave sensor to detect partial discharge signals, which enter the fault fitting unit after transformer transformation and differentiator conversion; The fault fitting unit uses transistor Q1 to connect +24V to one end of coil LA when the temperature signal of the cable joint measured after power consumption superposition correction is abnormal or the partial discharge is abnormal. The temperature signal of the cable joint measured after power consumption superposition correction is added to the base of transistor Q3. Transistor Q3 is connected to one end of coil LA, and coil LA is energized to fit the cable joint fault.

2. The monitoring device based on the optical fiber sensor cable joint according to claim 1, characterized in that: The temperature detection unit includes an optical fiber temperature sensor, which receives a cable joint temperature signal and an ambient temperature signal respectively. The cable joint temperature signal is connected to one end of the inductor L1, and the other end of the inductor L1 is respectively connected to one end of the grounding capacitor C1, one end of the resistor R3, the cathode of the diode D1, the anode of the diode D2, and the anode of the diode D3. The cathode of the diode D3 is connected to the cathode of the voltage regulator tube Z1. The ambient temperature signal is connected to the X pin of the multiplier ID1, and the Y pin of the multiplier ID1 is connected to the thermal conductivity corresponding to the size*material of the cable joint shell. The U0 pins of the multiplier ID1 are respectively One end of the resistor R1 and one end of the resistor R2 are connected, the other end of the resistor R1 is connected to the non-inverting input end of the operational amplifier AR1, the inverting input end of the operational amplifier AR1 is connected to the other end of the inductor L1 through the resistor R3, the output end of the operational amplifier AR1 is respectively connected to the upper end of the bidirectional voltage regulator SZ1 and the common end of the switch K1, the lower end of the bidirectional voltage regulator SZ1 is connected to the ground, the normally open contact of the switch K1 is connected to the positive electrode of the diode D1, the normally closed contact of the switch K1 is connected to the inverting input end of the operational amplifier AR2, and the non-inverting input end and output end of the operational amplifier AR2 are connected to the cathode of the diode D2.

3. The monitoring device based on the optical fiber sensor cable joint according to claim 1, characterized in that: The current detection unit includes an optical fiber current sensor, which measures the current when the cable is running. The square signal of the current is added to the X pin of the multiplier ID2, the Y pin of the multiplier ID2 is connected to the cable resistance R*time t, the U0 pin of the multiplier ID2 is connected to one end of the resistor R4, the other end of the resistor R4 is respectively connected to the inverting input end of the operational amplifier AR3, one end of the resistor R5, and the positive electrode of the electrolytic capacitor E3, the non-inverting input end of the operational amplifier AR3 is connected to the ground through the resistor R6, and the output end of the operational amplifier AR3 is respectively connected to the other end of the resistor R5, the negative electrode of the electrolytic capacitor E3, and the negative electrode of the voltage regulator tube Z1.

4. The monitoring device based on the optical fiber sensor cable joint according to claim 1, characterized in that: The partial discharge detection unit includes an optical fiber acoustic wave sensor, wherein one end of the optical fiber acoustic wave sensor for detecting partial discharge signal is added to one end of the inductor LA, one end of the resistor R8, and one end of the capacitor C2, and the other end of the capacitor C2 is connected to one end of the primary coil of the transformer T1, and the other end of the optical fiber acoustic wave sensor for detecting partial discharge signal is added to the other end of the inductor LA, the other end of the resistor R8, and the other end of the primary coil of the transformer T1, one end of the secondary coil of the transformer T1 is connected to one end of the inductor LB, and the other end of the inductor LB is connected to one end of the capacitor C3, and the other end of the capacitor C3 is respectively connected to one end of the resistor R9 and one end of the resistor R10, and one end of the secondary coil of the transformer T1 is respectively connected to the other end of the resistor R9 and one end of the resistor R12, and the The other end of the resistor R10 is respectively connected to the inverting input terminal of the operational amplifier AR4 and one end of the resistor R11, the other end of the resistor R12 is respectively connected to the non-inverting input terminal of the operational amplifier AR4, the output terminal of the operational amplifier AR4 is respectively connected to the negative electrode of the voltage regulator tube Z2 and one end of the resistor R13, the other end of the resistor R13 is respectively connected to one end of the resistor R14 and the inverting input terminal of the operational amplifier AR5, the non-inverting input terminal of the operational amplifier AR5 is connected to the ground through the resistor R15, the output terminal of the operational amplifier AR5 is respectively connected to the pin Y of the multiplier ID3 and one end of the resistor R16, the pin Y of the multiplier ID3 is connected to the reference partial discharge signal, and the pin U0 of the multiplier ID3 is connected to the other end of the resistor R14.

5. The monitoring device based on the optical fiber sensor cable joint according to claim 1, characterized in that: The fault fitting unit includes a transistor Q2 and a transistor Q3, the base of the transistor Q2 is respectively connected to the other end of the resistor R16 and the cathode of the diode D5, the anode of the diode D5 is respectively connected to the anode of the grounded electrolytic capacitor E3 and one end of the resistor R21, the other end of the resistor R21 is respectively connected to one end of the resistor R20, the anode of the voltage regulator Z1, and one end of the resistor R7, the other end of the resistor R7 is connected to the cathode of the voltage regulator Z1, the emitter of the transistor Q2 is connected to the drain of the field effect tube T1, the source of the field effect tube T1 is connected to the power supply +3.8V0, the gate of the field effect tube T1 is respectively connected to one end of the grounded resistor R19, the grounded electrolytic capacitor E 2, one end of resistor R18, and the positive electrode of electrolytic capacitor E1, the other end of resistor R18 is respectively connected to the negative electrode of electrolytic capacitor E1 and the positive electrode of voltage regulator Z2, the collector of transistor Q2 is connected to one end of resistor R17, the other end of resistor R17 is connected to the base of transistor Q1, the emitter of transistor Q1 is connected to power supply +24V0, the collector of transistor Q1 is respectively connected to one end of coil LA and the negative electrode of diode D4, the other end of resistor R20 is connected to the base of transistor Q3, the collector of transistor Q3 is respectively connected to the other end of coil LA and the negative electrode of diode D4, and the emitter of transistor Q3 is connected to ground through resistor R22.

6. The monitoring device based on the optical fiber sensor cable joint according to claim 1, characterized in that: The temperature detection unit, the current detection unit, the partial discharge detection unit, and the fault fitting unit are configured with a microprocessing unit, which communicates with a remote end through a communication module to remotely monitor the operating status and faults of the cable connector.

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